fix: added a new challenge

PairedSocks/PairedSocks.java

@@ -0,0 +1,39 @@
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Scanner;
+
+/**
+ * PairedSocks
+ */
+public class PairedSocks {
+  public static void main(String[] args) {
+
+    Scanner sc = new Scanner(System.in);
+    int n = sc.nextInt();
+    int[] randSocks = new int[n];
+    for (int i = 0; i < randSocks.length; i++) {
+      randSocks[i] = sc.nextInt();
+    }
+    sc.close();
+    int pairCounted = pairingSocks(n, randSocks);
+    System.out.println(pairCounted);
+  }
+
+  public static int pairingSocks(int n, int[] randSocks) {
+    int socks = 0;
+    Map<Integer, Integer> pairCount = new HashMap<>();
+    // we are gonna go through the array of integer and check if there is 2 paires
+    for (int x : randSocks) {
+      System.out.print(x + "\t");
+      pairCount.put(x, pairCount.getOrDefault(x, 0) + 1);
+    }
+    // count how many paires there is and return the sum.
+    System.out.println("\n");
+    for (int c : pairCount.values()) {
+      socks = socks + c / 2;
+    }
+    return socks;
+  }
+
+}